1. Field of the Invention
The present invention relates to electronic dictionaries and information retrieval apparatuses including, but not limited to, translating machines equipped with such electronic dictionaries.
2. Description of the Related Art
Language processing apparatuses in practical use at present include word processors for aiding a person in making documents, translating machines for translating a document written in one language into another language and the like. These language processing apparatuses are provided with dictionaries for storing information depending upon their respective purposes. The term "dictionary" as used herein indicates a systematic arrangement in which a number of unit items each formed of an entry and various sets of information associated thereto are integrated so that a desired item can be easily retrieved utilizing its entry.
The dictionary is principally stored in a machine-readable non-volatile medium in a machine-readable manner. Such a dictionary stored in a machine-readable non-volatile medium in a machine-readable manner will be referred to as an electronic dictionary. When an electronic dictionary is used for machine translation, a word string (including a single word) in an original language (source language) is used as an entry. Various information associated with that word string includes the part-of-speech information of the word string, a translation of the word string in a corresponding language (target language), etc.
Consider a user that is going to process or produce a document utilizing such a language processor. If the document contains a word which is not included as an entry in the dictionary associated with the processor, work efficiency greatly decreases. Therefore, as many entries as possible are desirably prestored in the dictionary. Similarly, for machine translation, idioms in, the original language are paired with corresponding expressions in the target language, and are stored as entries. It is desirable to register as many pairs of idioms with their expression to improve Work efficiency.
When, for example, idioms are registered as entries in a dictionary, however, the following disadvantage is encountered. Idioms are likely to include a portion changing its form such as number and part of speech, i.e., possessive pronoun, flexive pronoun, in relation to the subject and other parts of the sentence or phrase. In order to improve translation efficiency, many idioms with their variable parts replaced with specific words must be registered in the dictionary. This imposes an increased work load on a person trying to register words in the dictionary. Further, the more entries registered in the dictionary, the capacity of the recording medium necessary to store the dictionary will correspondingly increase. Therefore such a method of registration is not desirable.